accountService=cn.flypig666.service.impl.AccountServiceImpl

accountDao=cn.flypig666.dao.impl.AccountDaoImpl

 //定义一个Properties对象

     private static Properties props;

     //定义一个Map，用于存放我们要创建的对象，称之为容器

     private static Map<String,Object> beans;

     //使用静态代码块为Properties对象赋值

     static {

         try {

             //实例化对象

             props = new Properties();

             //获取properties文件的流对象,创建在resources文件夹下的properties文件会成为类根路径下的文件，不用写包名

             InputStream in = BeanFactory.class.getClassLoader().getResourceAsStream("bean.properties");

             props.load(in);

             //实例化容器

             beans = new HashMap<String, Object>();

             //取出配置文件中所有的 Key

             Enumeration  keys = props.keys();

             //遍历枚举

             while (keys.hasMoreElements()){

                 //取出每个key

                 String key = keys.nextElement().toString();

                 //根据key获取value

                 String beanPath = props.getProperty(key);

                 //反射创建对象

                 Object value = Class.forName(beanPath).newInstance();

                 //把key和value存入容器中

                 beans.put(key,value);

             }

         } catch (Exception e) {

             throw new ExceptionInInitializerError("初始化properties失败");

         }

     }

     public static Object getBean(String beanName){

         return beans.get(beanName);

     }

     /**

      * 根据Bean的名称获取bean对象

      * @param beanName

      * @return

      */

     public static Object getBean(String beanName){

         Object bean = null;

         try{

             String beanPath = props.getProperty(beanName);

             System.out.println(beanPath);

             bean = Class.forName(beanPath).newInstance();

         }catch (Exception e){

             e.printStackTrace();

         }

         return bean;

     }

 }

/**

 * 账户业务层实现类

 */

public class AccountServiceImpl implements IAccountService {

    //private IAccountDao accountDao = new AccountDaoImpl();

    private IAccountDao accountDao = (IAccountDao) BeanFactory.getBean("accountDao");

    public void saveAccount(){

        accountDao.saveAccount();

    }

}

/**

 * 模拟一个表现层，用于调用业务层

 */

public class Client {

    public static void main(String[] args) {

//        IAccountService accountService = new AccountServiceImpl();

        IAccountService accountService = (IAccountService) BeanFactory.getBean("accountService");

        accountService.saveAccount();

    }

}